Warm Surfaces Of Electronic Devices And Human Thermal Responses
Heat dissipation is an essential consideration for the hardware design of the handheld electronic devices. For such devices the surface temperature needs to be maintained at a level that is comfortable and that will not create risks of skin burn or user thermal discomfort. As the packaging of handheld electronic devices becomes smaller and thinner, effectively dissipating the heat generated by components such as central processing unit, power supply and batteries, while maintaining a comfortable and safe surface temperature, is becoming more challenging. Current standards provide information on the maximum surface temperature to prevent skin burns, but not user thermal comfort. Many experimental studies have investigated the skin temperature thresholds for thermal sensation and heat pain. However, only limited research exists on how users' cutaneous thermal sensation and comfort is affected by prolonged duration in contact with electronic devices. Research is also lacking on the effects of heat distribution patterns and the characteristics of surface materials. In the present work a comprehensive literature review was conducted on various aspects related to thermal sensation and comfort. A preliminary survey was completed to understand laptop users' thermal comfort and its relation with surface temperature. A novel tablet-size heating surface was developed. Afterwards, a series of experiments was completed to systematically investigate how finger and palm thermal sensation and comfort were affected by the following variables: the surface temperature, the ambient temperature, the rate of surface temperature change, the spatial distribution of the heat, and the roughness of texture. Results from these studies have practical implications for the future design of handheld electronic devices. Future research also may focus on extending the current work to study more varied user tasks and other body parts that may be in contact with future electronic devices.
Thermal comfort; Product design; Ergonomics
Cosley,Daniel R.; Booth,James
Human Behavior and Design
Ph.D. of Human Behavior and Design
Doctor of Philosophy
dissertation or thesis